Showing papers on "Turbinaria ornata published in 2010"

Turbinaria ornata as an herbivory refuge for associate algae

Abstract: Habitat associations are an integral part of coral reef community structure. Commonly, one organism lives in such close association within or near another that a spatial refuge occurs, whereby one of the organisms provides protection to the other. This is often the result of defenses of the host deterring an associate organism’s consumers. In Moorea, French Polynesia, the range and abundance of the brown macroalga, Turbinaria ornata, have increased drastically since 1980 such that dense aggregations of this macroalga are a dominant component of the backreef habitat. Turbinaria ornata is both mechanically and chemically defended from herbivores. Other species of macroalgae grow within aggregations of Turbinaria and may benefit from these defenses. This study investigates whether aggregations of Turbinaria create a refuge from herbivory for associate macroalgae. When Turbinaria aggregations were removed experimentally, there was a significant increase in the number of associate algal species. Moreover, an herbivory assay using the palatable local alga Acanthophora spicifera identified herbivory as the mechanism for lower diversity on bommies lacking Turbinaria aggregations. The local increase in algal richness due to the refuge from herbivory afforded by Turbinaria may be an important contribution to macroalgal and community dynamics on reefs in Moorea, French Polynesia.

Trace elements of spring and winter macroalgae in liusha bay

Abstract: Concentrations of As, Se, Cu, Pb, Zn, Cd, Cr, Fe, Mn, and Ba in 21 macro-algae from Liusha Bay (the west of Xuwen Country, Guangdong Province) in spring and winter 2008 were determined by Atomic Fluorescence Analyzer (AFA) and Inductively Coupled Plasma Mass Spectrometer (ICP-MS). The results show that the concentration of heavy metal was enriched in different algae. For example, Gracilaria conferuoides had the highest concentration of As, Cu, Pb, Cr, Se, Fe, Mn, at 8.9, 34.35, 24.26, 68.12, 12.04, 26777.2, and 400.16mg/kg; and Nemacysti Decipientis, Sargassum thunbergii, Gelidium amansii, Asparagopsis taxiformis for Hg, Zn, Cd, Ba at 6.9, 277.37, 6.77, 127.02mg/kg, respectively. The order of heavy-metal bioaccumulation degree is: Gracilaria conferuoides Cladophoropsis herpestica Ectocarpus Nemacysti Decipientis Sargassum thunbergii Asparagopsis taxiformis Enteromorpha clathrata Corallina pilulifera Enteromopha intestinalis Grateloupia filicina Monostroma nitidum Gelidium pacifieum Okam. Gelidium amansii Padina sp. Ulva stenophylla Amphiroa anceps Lamouroux Acanthophora spicifera Turbinaria ornata Plo- camium telfairiae Cladophora sp.. Moreover, the magnitude order of average concentration of heavy metals accumulated in different algae is: Fe Mn Ba Zn Cr Cu Pb As Se Cd Hg, and the bio-enrichiable nutrients elements are richer in the algae than toxic elements. Different algae are very different in the bioaccumulation coefficient varying from several to hundreds of thousands of times, and so for each species for different heavy metals. The highest value was found in Gracilaria conferuoides for Fe enrichment with bioaccumulation coefficient at 204875.29, followed by Nemacysti decipientis for Hg at 13800.00; and the least one was Cladophora sp. for Se at only 3.48. No individual alga had strong accumulation of every heavy metal. Cluster analysis showed that Gracilaria conferuoides was the strongest one capable of bio-accumulation, and can be selected to treat heavy-metal polluted waters. However, to remedy large-area heavy-metal contaminated waters, combination of several capable algae is recommended for better ecological restoration.

Habitat-related allelic variation revealed by an anonymous DNA locus in reef-dwelling Turbinaria ornata (Fucales, Phaeophyceae)

Abstract: We assessed genetic polymorphism of a bi-allelic anonymous DNA locus in otherwise highly homogeneous Turbinaria ornata populations in French Polynesia, Hawaii, Solomon, Wallis and La Reunion Islands. Large heterozygote deficien- cies occurred in almost all populations, which may be related to possible self-fertilisation and short dispersal distance of zygotes. There was a high genetic differentiation among samples (Fsts0.5269***) and this was correlated with a gra- dient of hydrodynamic conditions prevailing on French Polynesian coral reefs. This correlation is tentatively asso- ciated with balancing selection acting on, or on the vicinity of, this anonymous DNA locus.